1. Field of the Invention
The present invention relates to method and devices for removing a predetermined amount of breast tissue for the purposes of treatment and/or microscopic examination.
2. Description of the Background Art
Wire needle localization (WNL) is a surgical technique frequently invoked by surgeons to biopsy lesions in the breast discovered as a result of mammography or other breast screening methods. Patients undergoing WNL are placed on a radiographic table usually located in the radiology suite. The breast is placed between two compression plates, arranged moveably in relation to one another, for fixing the breast therebetween. The compression plates have through holes which permit the introduction of a biopsy needle into the breast and proximate to the breast lesion under radiographic guidance. Once the needle is placed in the desired position in the breast, a thin, stiff wire with a distal retaining hook is inserted through the lumen of the needle. As the wire emerges from the distal aspect of the needle, the distal hook of the wire engages the breast tissue proximate to the breast lesion. The needle is withdrawn leaving the hook wire proximate to the lesion. The position of the wire relative to the lesion is verified radiographically. Radiographic views of the wire in the breast are taken and brought to the operating so as to allow the surgeon to plan the surgical biopsy procedure.
The patient is transferred to the operating room. The surgeon plans his approach to surgically retrieving and adequate tissue specimen after physically examining and reviewing the radiographs of the breast with the wire placed in proximity to the breast lesion. The wire serves as a marker which can be palpated by the surgeon at the time of and during surgery which serves as a marker during surgery. Local anesthetic is administered in and around the proposed surgical area. An incision is made and the surgeon dissects around the wire. During the dissection, the surgeon continuously palpates the location of the wire in order to orient the dissection and determine that amount of tissue to be harvested or biopsied.
The surgical objective of the biopsy is to remove an adequate tissue sample such that the wire and the lesion are at the center of the sample surrounded by an adequate margin thickness of normal breast tissue. In other words, the ideal specimen can be compared to a peach wherein the pit or seed is analogous to the lesion and the pulp completely surrounding the seed is analogous to normal tissue.
WNL is a useful technique for surgically excising an amount of tissue adjacent to a palpable landmark such as a wire. However, the surgeon is often confronted with making an intraoperative estimation of the amount of tissue to be biopsied by the radiograph appearance of the lesion and its relative location to the wire as well as intraoperative findings and surgical approach to the wire. In addition, instrumentation or techniques for open surgical breast biopsies that remove a predetermined amount of breast tissue are not currently known or practiced.
Objects of the Invention. It is an object of the present invention to provide method and devices which allows surgeons to remove a predetermined amount of breast tissue based on radiographic findings of the lesion to be biopsied.
It is another object of the present invention to provide an over the wire device to make and incision and dissect tissue along a path determined by the placement of a scalpel over a wire.
It is still another object of the invention to provide an over the wire tissue harvester device that uses energy to cut a predetermined amount of tissue for the purposes of treatment or examination.
Summary of the Invention. The present invention relates to surgically removing a predetermined amount of breast tissue for treatment and/or microscopic examination. More particularly, the invention describes a method employing apparatuses including a small, stiff guide wire placed adjacent to the lesion to be biopsied, an over the wire scalpel, and an over the wire tissue harvester. The method and associated devices employed in the invention consists of four steps, namely (1) placement of the wire proximate to the breast lesion under radiographic guidance, (2) using a graduate template and a radiograph of the wire placed in the breast proximate to the breast lesion to be removed, measurements of the proposed breast tissue to be surgically removed are made, (3) from these measurements, selection of the appropriate scalpel is made, then placed over the wire and advanced resulting in a skin incision, creating access to the lesion, and working space to the desired level within the breast, and (4) from the incision and the measurements, the appropriate tissue harvester is selected and advanced over the wire to the desired position and secured, then the hoop is actuated simultaneous to the activation of electrical energy through the hoop and a predetermined amount of breast tissue is swathed by the action of the hoop rotating about its pinned position at the most distal aspect of the tissue harvester. In one embodiment a trailing bag can be attached to the hoop to enclosed the breast tissue to be removed as the hoop traverses through the breast tissue. In yet another embodiment, the wire is scored so the surgical position can be related to the radiographic position.